Side-scan sonar systems are typically configured to detect acoustic radiation within a fan-shaped region that is narrow in a plane parallel to motion of a water vessel and broad in a plane perpendicular to the motion of the vessel. Interferometric sonar measurements using multiple transducer detector elements can be used to determine a direction of an object detected in the water with respect to the water vessel with greater specificity. Phase differences between signals received at multiple acoustic transducers can be used to determine the arrival angle for an acoustic signal detected by the transducers.
However, aliasing can occur when the phase difference between signals received at the multiple transducers exceeds 360° (phase wrapping), corresponding to one complete temporal or spatial cycle of the received acoustic radiation. Aliasing limits the range of arrival angles that can be reliably determined with a given set of transducer elements.